This is still a WIP It is designed to hold 12 spools on wheels mounted to 8mm (5/16") rods. I used plywood and dowels for mine but I will create a version that can be printed in the near future. If you are going to feed from the box feed the filament through bowden connectors using the pass through (screw them on with M3 screws). The bearings used for the wheels are 608 ZZ.